Add support for reading blobs when using the network service.

content/browser/blob_storage/blob_url_loader_factory.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_BLOB_STORAGE_BLOB_URL_LOADER_FACTORY_H_
+#define CONTENT_BROWSER_BLOB_STORAGE_BLOB_URL_LOADER_FACTORY_H_
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "content/common/url_loader_factory.mojom.h"
+#include "content/public/browser/browser_thread.h"
+#include "mojo/public/cpp/bindings/binding_set.h"
+
+namespace storage {
+class FileSystemContext;
+}
+
+namespace content {
+class ChromeBlobStorageContext;
+class StoragePartitionImpl;
+
+// A class for creating URLLoaderFactory for blob scheme.
+// There should be one owned per StoragePartition.
+class BlobURLLoaderFactory
+    : public base::RefCountedThreadSafe<BlobURLLoaderFactory,

[dmurph, 2017/05/25 21:37:10]

Can we make this not refcounted?

[jam, 2017/05/26 04:46:47]

It's used on StoragePartition and passed to the IO thread, hence the ref
counting. All the member classes there are similarly refcounted.

+                                        BrowserThread::DeleteOnIOThread>,
+      public mojom::URLLoaderFactory {
+ public:
+  explicit BlobURLLoaderFactory(StoragePartitionImpl* storage_partition);
+
+  // Creates a URLLoaderFactory interface pointer for serving blob requests.
+  // Called on the UI thread.
+  mojom::URLLoaderFactoryPtr CreateFactory();
+
+ private:
+  friend class base::DeleteHelper<BlobURLLoaderFactory>;
+  friend struct BrowserThread::DeleteOnThread<BrowserThread::IO>;
+
+  ~BlobURLLoaderFactory() override;
+
+  void BindOnIO(mojom::URLLoaderFactoryRequest request);
+
+  // mojom::URLLoaderFactory implementation:
+  void CreateLoaderAndStart(mojom::URLLoaderAssociatedRequest loader,
+                            int32_t routing_id,
+                            int32_t request_id,
+                            uint32_t options,
+                            const ResourceRequest& request,
+                            mojom::URLLoaderClientPtr client) override;
+  void SyncLoad(int32_t routing_id,
+                int32_t request_id,
+                const ResourceRequest& request,
+                SyncLoadCallback callback) override;
+
+  scoped_refptr<ChromeBlobStorageContext> blob_storage_context_;
+  scoped_refptr<storage::FileSystemContext> file_system_context_;
+
+  // Used on the IO thread.
+  mojo::BindingSet<mojom::URLLoaderFactory> loader_factory_bindings_;
+
+  DISALLOW_COPY_AND_ASSIGN(BlobURLLoaderFactory);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_BLOB_STORAGE_BLOB_URL_LOADER_FACTORY_H_